Sesame oil mitigates nutritional steatohepatitis via attenuation of oxidative stress and inflammation: a tale of two-hit hypothesis.

Nonalcoholic fatty liver disease, the most common chronic liver disorder worldwide, comprises conditions from steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. NASH is associated with an increased risk of hepatocellular carcinoma. Sesame oil, a healthful food, increases resistance to oxidative stress, inflammation and protects against multiple organ injury in various animal models. We investigated the protective effect of sesame oil against nutritional steatohepatitis in mice. C57BL/6 J mice were fed with methionine-choline deficient (MCD) diet for 28 days to induce NASH. Sesame oil (1 and 2 ml/kg) was treated from 22nd to 28th day. Body weight, steatosis, triglycerides, aspartate transaminase, alanine transaminase, nitric oxide, malondialdehyde, tumor necrosis factor-α, interlukin-6, interleukin-1β, leptin, and transforming growth factor-β1 (TGF-β1) were assessed after 28 days. All tested parameters were higher in MCD-fed mice than in normal control mice. Mice fed with MCD diet for 4 weeks showed severe liver injury with steatosis, oxidative stress, and necrotic inflammation. In sesame-oil-treated mice, all tested parameters were significantly attenuated compared with MCD-alone mice. Sesame oil inhibited oxidative stress, inflammatory cytokines, leptin, and TGF-β1 in MCD-fed mice. In addition, histological analysis showed that sesame oil provided significant protection against fibrotic collagen. We conclude that sesame oil protects against steatohepatitic fibrosis by decreasing oxidative stress, inflammatory cytokines, leptin and TGF-β1.